Fix Bacula catalog backup job and restore from FTP

1. The catalog backup job needs to run at the lowest priority.

   I'm not sure if that's why the make_catalog_backup.pl script has
   created a broken dump file (with a "database is locked" error in
   it), but it's definitely best to run it at the lowest priority.

2. Bacula's "bls" is terrible.  It only takes a handful of volumes
   to scan on the command line and discards the rest.  To scan more
   volumes the list must be written to a .bsr file.
Give a useful error if bconsole failed to start
Implement a way to run all backup and all restore jobs

To do a full backup of a client:

$ sudo bacula-backup --all

To do a full restore of a client:

$ sudo bacula-restore --all

Additional options are --client (for backup), --restoreclient
(for restore) and --force to continue even when some jobs fail.